3d-beam modulation filter for equalizing dose and image quality in breast ct

Patent metadata

Field	Value
Publication number	US-2018317867-A1
Application number	US-201615779342-A
Country	US
Kind code	A1
Filing date	Nov 23, 2016
Priority date	Nov 25, 2015
Publication date	Nov 8, 2018
Grant date	—

Abstract

A size and/or shape specific 3D-beam modulation filter and a size and/or shape specific immobilizer are provided for cone-beam breast computed tomography (bCT). The immobilizer places the breast on an optimal position in the field of view of the scanner system and the 3D-beam modulation filter modulates the incident x-ray beam in the cone-angle (i.e. z-axis of the detector panel) and fan angle (i.e. x-axis of the detector panel) directions in order to improve equalization of the photon fluence incident upon the detector panel and reduce unnecessary radiation dose that the breast receives. Both the immobilizer and the 3D-beam modulation filter are selected among a plurality of alternatives based on the specific shape, size and/or shape or size of the person's breast.

First claim

What is claimed is:

1 . A method for acquiring a computed tomography (CT) image of a body part using a scanner system comprising:
selecting an immobilizer among a plurality of immobilizers based on a shape or size of the body part; selecting a 3D-beam modulation filter among a plurality of 3D-beam modulation filters based on the shape or size of the body part; placing the 3D-beam modulation filter at a predetermined distance from an x-ray source of the scanner system; coupling the selected immobilizer to the scanner system; positioning the body part in the selected immobilizer; acquiring a computed tomography (CT) image of the body part using the scanner system including the 3D-beam modulation filter.

2 . The method of claim 1 , wherein the body part is a breast.

3 . The method of claim 2 , wherein the 3D-beam modulation filter is configured to reduce a dose of radiation toward anterior and peripheral regions of the breast.

4 . The method of claim 1 , wherein acquiring the CT image of the body part further comprises:
collecting x-rays beams emitted from the x-ray source of the scanner system on a detector panel of the scanner system, wherein the x-ray beams emitted by the x-ray source are filtered by the 3D-beam modulation filter prior to traveling through the body part.

5 . The method of claim 1 , further comprising:
dynamically adjusting a position of the 3D-beam modulation filter prior to acquiring the computed tomography (CT) image of the body part.

6 . The method of claim 1 , further comprising:
identifying a predetermined profile among a plurality of predetermined profiles based on the shape or size of the body part, wherein each of the plurality of 3D-beam modulation filters and each of the immobilizers are generated for one of the plurality of predetermined profiles.

7 . The method of claim 6 , further comprising:
forming a plurality of molds corresponding to the plurality of predetermined profiles; and producing the plurality of immobilizers using the plurality of molds, wherein the producing comprising:
producing a first immobilizer using a first mold corresponding to a first predetermined profile, and
producing a second immobilizer using a second mold corresponding to a second predetermined profile.

8 . The method of claim 1 wherein the 3D-beam modulation filter is a combined filter, the method further comprising:
selecting a bowtie-shaped filter among a plurality of bowtie-shaped filters based on the shape or size of the body part;
selecting a wedge-shaped filter among a plurality of wedge-shaped filter based on the shape or size of the body part; and
combining the selected bowtie-shaped filter and the selected wedge-shaped filter into the combined filter.

9 . The method of claim 1 , wherein coupling the selected immobilizer to the scantier system further comprises:
attaching a first end of an attachment element to a surface of the scanner system, and attaching second end of the attachment element to the selected immobilizer.

10 . The method of claim 9 , wherein the attachment element includes a flange or a fastener.

11 . The method of claim 1 , further comprising:
acquiring two orthogonal scout views of the body part; adjusting a position of the 3D-beam modulation filter or the body part based on the acquired orthogonal scout views of the body part.

12 . A computing device including a non-transitory storage medium storing instructions, and a processor executing the instructions stored on the non-transitory storage medium to perform the method of claim 1 .

13 . A computed tomography (CT) scanner system including:
an x-ray production system including an x-ray source emitting x-ray beams; an x-ray detector system for receiving the x-ray beams emitted by the x-ray source; a 3D-beam modulation filter positioned between the x-ray source and the detector system at a predetermined distance from the x-ray source, wherein the 3D-beam modulation filter is specific to a predetermined body part shape or size; a gantry assembly system including a surface for receiving a body part to be imaged, wherein the body part conforms to the predetermined body part shape or size; and an immobilizer coupled to the gantry assembly system, wherein the immobilizer is specific to the predetermined body part shape or size.

14 . The CT scanner system of claim 13 further comprising:
a scanner control computer coupled to the x-ray production system and the gantry assembly system for sending control signals to the x-ray production system and the gantry assembly system.

15 . The CT scanner system of claim 13 further comprising:
a filter positioning system for selecting the 3D-beam modulation filter among a plurality of 3D-beam modulation filters based on the predetermined body part shape or size, and for positioning the 3D-beam modulation filter between the x-ray source and the detector system at the predetermined distance from the x-ray source.

16 . The CT scanner system of claim 15 , wherein the 3D-beam modulation filter includes a combined filter, wherein the filter positioning system is further configured to:
select a bowtie-shaped filter among a plurality of bowtie-shaped filters based on the predetermined body part shape or size; select a wedge-shaped filter among a plurality of wedge-shaped filter based on the predetermined body part shape or size; and combine the selected bowtie-shaped filter and the selected wedge-shaped filter into the combined filter.

17 . The CT scanner system of claim 13 further comprising:
an image acquisition computer for receiving image data from the x-ray detector system;
an image reconstruction computer for reconstructing the CT image of the body part based on the image data received from the image acquisition computer; and
a display for displaying the reconstructed CT image of the body part.

18 . The CT scanner system of claim 17 , wherein the image reconstruction computer receives receive data from the scanner control computer and the image acquisition computer, the data including one or more of x-ray beam intensity data, x-ray beam emission timing data, gantry assembly system positioning data, or projection images of the body part being imaged.

19 . The CT scanner system of claim 13 , wherein the body part is a breast and the 3D-beam modulation filter is configured to reduce a dose of radiation toward anterior and peripheral regions of the breast.

20 . The CT scanner system of claim 13 , wherein the immobilizer is coupled to the gantry assembly system using one or more attachment elements.

Assignees

• Univ California

Inventors

• Boone John M
• Hernandez Andrew M
• Gazi Peymon

Classifications

• A61B6/4035

  the source being combined with a filter or grating · CPC title

• A61B6/4085 Primary

  Cone-beams · CPC title

• A61B6/4078

  Fan-beams · CPC title

• A61B6/583

  using calibration phantoms · CPC title

• A61B6/5205

  involving processing of raw data to produce diagnostic data · CPC title